The present invention relates to technology about sorting various kinds of sheets of paper, and more particularly to the technology which may be effectively applied to the sorting of various kinds of sheets of paper such as postcards and cards used in an information processing field.
For example, in the process of sorting a massive amount of postcards, the operation is executed to recognize character information containing a zip code and an address described on each postcard through the effect of the known OCR technology and activate a distributing mechanism in concert with the recognizing operation for automatically distributing the postcards to the corresponding destination areas. This operation makes it possible to achieve a saving in labor and speed up the work.
A conventional construction for executing the aforementioned operation is illustrated in FIG. 12. FIGS. 10A and 10B illustrate an exemplary system for conveying various kinds of sheets of paper 10 (simply called sheets). The sheets 10 are separated one by one by a separating mechanism 1011 located in a separating section 1001 so that each sheet is transferred to a conveying path. A numeral 1012 denotes a recognizing mechanism, which reads, for example, an address described in each sheet and then recognizes the read address through a desired algorithm stored in a computer. The time consumed by the recognition depends on the conveying path on which the sheets are conveyed. For apparatus' convenience' sake, this conveying path is located in a space 5 secured under the lowest row of boxes 1041 of a sorting section 1044. While the postcard is being conveyed on the conveying path, the characters of the address, for example, are recognized. Then, the postcard is sorted into the corresponding box 1041 through the effect of the sorting section 1044. However, if the characters are not recognized between the recognizing mechanism 1012 and the sorting section 1044, the postcard must be rejected. The frequent rejections become an obstacle to enhancing the operativity of the sorting apparatus. Hence, the improvement of the recognition factor is important in enhancing the operativity of the sorting apparatus. For quickly recognizing various kinds of characters, there must be provided an expensive computer for achieving the fast processing.
If the recognition is disabled, in recent days, a video coding system has been reviewed, in which the picture data scanned in recognizing the characters is displayed on a CRT so that an operator can read the unrecognized characters and manually enter the read characters to the apparatus. This video coding system does to need an expensive computer for recognizing the characters but needs a considerable length of time in the operator's recognition and input of the character information. Hence, this considerable length of time requires a long conveying path. The long conveying path, however, burdens the apparatus with a technical issue. That is, it needs an additional path to the outside of the apparatus, so that the path makes the apparatus larger in size. The resulting longer apparatus is not allowed to be stored a limited area, thereby making the installing area of the apparatus wider.
On the other hand, turning to an interval between the sheets 10 being separated by the separating section 1001 and conveyed on the conveying path, as illustrated in FIGS. 10A and 10B, the system currently employed about this point may be roughly divided into two systems, that is, a constant pitch system (see FIG. 10A) and a constant gap system (see FIG. 10B). The constant pitch system is arranged to keep the distance (pitch P) between the tail end of the leading sheet 10 and the tail end of the succeeding sheet 10 constant. The constant gap system is arranged to keep the distance (gap G) between the tail end of the leading sheet 10 and the front end of the succeeding sheet 10.
As illustrated in FIG. 12, as a main technical current, the separating mechanism 1011 located in the conventional separating section 1001 is constructed to separate the sheets 10 horizontally arranged in a standing manner toward the upward part from the ranging end. The constant pitch system is advantageous in this construction. This is because since the feeding lengths of the sheets 10 are varied, if the constant pitch system is employed, the upwardly separating system may be implemented by such a simple control operation as sending the tail end of the leading sheet 10 and then feeding out the succeeding sheet 10 after a predetermined time defined by the feeding speed and the pitch.
As described above, in a case that an expensive computer is not necessary if an operator's manual operation to be put to the overall process can compensate for a lower recognition factor to some extent, it is necessary to secure a sufficiently long conveying path without making the overall length of the apparatus longer. A bypass located in a narrower space entails a smaller curvature. The bypass with a small curvature puts a burden on the sheets, so that the sheets may be impaired and often jammed. In order to overcome these shortcomings, it is preferable to provide such a technique as allowing a relatively long conveying path to be located in a limited space without impairing the sheets being conveyed.
For the foregoing constant pitch system adapted to the upwardly separating system, since the sheets 1 have their respective lengths (heights), between the tail end of each leading sheet 10 and the front end of the succeeding sheet 10, the times passed therebetween is made variable. The box 1041 located in the sorting section 1044 has a gate 1042 for opening or shutting the gate. By controlling the timing when the sheet 10 comes to the gate 1042 and the timing when the gate 1042 is opened or shut, it is determined whether or not the passing sheet 10 is put in each box 1041. A short pitch may cause an erroneous operation or jamming. In order to avoid this disadvantage, the pitch is considered to be far larger than each length of the variable sheets 10. If, however, the pitch is larger than necessary, the number of the sheets 10 to be processed at a unit time, that is, a throughput is made lower. On the other hand, if the constant gap system is used, that is, the upwardly separating system, it may present another technical problem. That is, one alternative has to be, selected, a lower throughput required in the case of considering the variable lengths (heights) or a wider pitch P required in the case of speeding up the conveying speed.